mcts training kit 70 - 652 server virtualization phần 5 pot

In the case of a course requiring several machines working together, such as a Microsoft Windows SharePoint course, one parent disk is created with a core installation of Windows Server

disk type descriptiOn

Differencing disks are used in a wide number of situations For example, Microsoft Learning uses the differencing disk concept to create all

of the training machines used in the courses they deliver In the case

of a course requiring several machines working together, such as a Microsoft Windows SharePoint course, one parent disk is created with

a core installation of Windows Server 2008 and multiple child disks are created with the required server roles such as one for Active Directory Domain Services, one for Exchange Server, one for SQL Server, one for SharePoint Server, and so on When the entire environment runs, each server role boots from the core parent disk and then the child disks run

to create the required environment

Because differencing disks are based on a single parent, performance can be very poor unless you run differencing disks on the fastest spindles you have access to However, because of the parent-child relationship, differencing disks can save significant amounts of actual disk space because the parent disk is the disk that requires the largest amount of space and the child disks only store actual differences or changes made beyond the base parent disk In the case

of the MS Learning disk example, you can often create very complex environments with only a few gigabytes of used space

A parent can have multiple different and unrelated child disks such

as in the case of installing different products on different child disks

or it can have a hierarchical relationship to child disks, with each child becoming the parent of the next child disk as new child disks are created The latter is what happens when you use the Hyper-V Snapshot feature because you automatically turn the existing VHD into

a set of differencing disks Each time you create a snapshot, you create

a new parent-child relationship between the VHDs

Differencing disks are often best used in training, testing, or development environments because they always allow you to go back

in time by breaking the parent-child relationship and return to a given state of the VM

The three disk types listed in Table 4-3 make up the different types of disks you will normally work with in Hyper-V (see Figure 4-10)

More Info virtuaL Hard disks

For more information on working with virtual hard disks, look up the screen cast Working

with VHDs at http://go.techtarget.com/r/5927599/30819

Allocated Disk Size

Used Disk Space

figure 4-10 Hyper-V VHD types

Update alert HOt add vHds

VHDs are now a standard part of Windows Server 2008 R2 and Windows 7 For example,

when you add a new disk in Disk Manager, you can create, format and consume VHDs

directly from the interface Because of this, you can now dynamically add or remove VHDs

to running VMs Note however that VHDs must be tied to SCSI controllers to use this

feature You can also add or remove pass-through disks to running VMs so long as the

disks are tied to SCSI controllers Windows Server 2008 R2 and Windows 7 can also boot

from VHDs making it easier to consume this powerful disk format directly from the OS.

You can store any of the three VHD types on physical hard disk volumes that can be in

either direct-attached storage (DAS), network-attached storage (NAS), or storage area network

(SAN) in nature However, you must store them on partitions that are formatted with NTFS You

cannot store Hyper-V VHDs in folders that use the Encrypting File System (EFS) because EFS is

an encrypting system that is usually tied to particular users, and storing VHDs in user profiles

does not make them highly available because they must run in a single user’s context

If security is an issue, you can store VHDs on partitions that use the BitLocker full drive

encryption system However, note that BitLocker adds some overhead to disk operations, which

may impact VHD I/O operations and therefore virtual machine performance Use BitLocker

encryption only in highly secure environments or in environments where the possibility of theft

is present The latter could occur in remote sites or in branch office locations where access to host servers cannot be secured because of the lack of a lockable storage room for servers.Ideally, your VHDs will be stored on a high-speed shared storage container that is accessible

by multiple Hyper-V hosts Using this strategy ensures virtual machine fault tolerance because the VM can run on any of the hosts that have access to the shared storage LUN without having

to actually duplicate or replicate the VHDs from one location to another VHD replication can take considerable time because they can range in size from 40 to many hundreds of gigabytes Note that the maximum size of a VHD in Hyper-V is almost 2 terabytes and is set at 2,040 GB

exaM tIp maximum vHd size

Remember that the maximum VHD size in Hyper-V is actually 8 GB short of 2 terabytes and

is set to 2,040 GB instead of 2,048 GB This item will definitely be in the questions you’ll find on the exam.

Avoid running VHDs on system disks that are used to run the parent partition

Working with Pass-through Disks

A fourth type of disk you can use in support of virtual machines in Hyper-V is the

pass-through disk Pass-through disks are physical disk partitions that are assigned to a virtual machine Instead of using a virtual hard disk, you assign an actual physical partition

to the VHD Pass-through disks have the following features:

n performance Pass-through disks will give your VMs the utmost performance because

Hyper-V does not need to manage the virtual disk during the operation of the virtual machine When a VM runs, Hyper-V is only responsible for the actual operation of the

VM and only needs to assign processor, memory, and networking resources to the VM

n Hybrid vms When you use pass-through disks, you can create a hybrid VM using a

VHD as the system disk and using pass-through disks for the data disks For example,

if you created a VM to host Exchange Mailbox Server, you might store the operating system on a small VHD tied to the IDE controller, then install all Exchange services

on a second drive that is a pass-through disk You could then assign additional pass-through disks for the messaging database and the transaction logs, ensuring the best performance for the Exchange Mailbox Service

n pass-through disk connections Hyper-V VMs must boot from an IDE drive

Fortunately, you can assign a pass-through disk to a VM’s IDE controller You can also assign pass-through disks to both SCSI and iSCSI controllers, but they must be for disks other than the boot or system disk

n Locked-in vms Using pass-through disks locks the VM into the physical configuration

you use to create it The whole point of a virtual machine is that it is nothing but a set of files in a folder When this is the case, you can create a VM in London, copy its files to New York, and then run the VM in New York But when you use pass-through disks, you limit

the VM’s mobility in much the same way you limit the mobility of a physical machine when

you install an operating system physically You must then find a way to move the contents

of the physical disks the VM is composed of to another location to move the VM To do

this, you will often have to re-create the VM in its destination location or at the very least

change its disk connections in the VM settings because they will no longer be the same

n Hybrid pass-through disks You can also create hybrid pass-through disks For

example, you cannot boot a VM from an iSCSI controller, but you can boot a VM from

an IDE controller that is tied to an iSCSI pass-through disk Here’s how:

1. Create a LUN in your shared storage container to host the boot and system

partitions for the VM

2. Use iSCSI to attach the LUN to the parent partition of a Hyper-V host To avoid

contention for the disk between the host and the VM, make sure the new LUN is

offline on the host server

3. Create your new VM and choose to create the disk drives that will run it after the

VM is created

4. Move to the VM’s settings and select IDE Controller 0 and Location 0 (In Use) and

assign it to a Physical Hard Disk Select the disk you attached through the iSCSI LUN

5. Save your changes and boot the VM The VM will boot from the iSCSI LUN You

can then install an operating system and run it from the iSCSI LUN

n enlightened or Legacy guests Both enlightened and legacy guest operating systems

can use pass-through disks; however, legacy guests are limited to IDE functionality and

cannot use SCSI pass-through disks

As you can see, pass-through disks can provide a viable option for several system

configurations, but they limit VM functionality and do not give you access to any of the VHD

capabilities that make VMs so much more exciting than physical machines

exaM tIp maximum pass-tHrOugH disk size

Remember that the maximum pass-through disk size in a VM is limited only by the

limitations of the operating system running in the VM, not by Hyper-V’s limitations

Using IDE or SCSI Disks

When you attached disks to VMs, you must select how to attach the disk to the VM Three

possibilities exist:

n integrated drive electronics (ide) When you attach a disk—either VHD or

pass-through—to a VM through an IDE controller, you attach a virtual Advanced

Technology Attachment (ATA) disk to the VM You can attach up to four virtual IDE

disks to a VM Note that IDE controllers are created automatically when you create a

VM Both enlightened and legacy guest operating systems can use IDE controllers in

Hyper-V Also note that Hyper-V VMs must boot from a virtual IDE disk

n small computing system interface (scsi) When you attach a disk to a VM through

the SCSI controller, you attach a virtual SCSI disk to the VM However, because SCSI controllers are not created automatically during VM creation, you must create them after the VM has been generated through the New Machine Wizard in Hyper-V This

is done through the VM’s Settings dialog box under Add Hardware and then SCSI Controller You can attach up to four SCSI controllers to a VM Each SCSI controller can support 64 disks for a maximum of 256 virtual SCSI disks on a guest operating system Note, however, that SCSI controllers are only available to enlightened guest operating systems that have Integration Services installed

exaM tIp Linux integratiOn cOmpOnents

Remember that LIC contain support for SCSI controllers just as the Integration Services do for Hyper-V–aware Windows guest operating systems, but do not include graphics drivers.

n internet scsi (iscsi) You can also attach disks directly to VMs through iSCSI initiators

For example, Windows Server 2008 includes the iSCSI initiator directly within the operating system You can use this initiator to bypass the host operating system completely and expose a disk only to the VM it runs You do this by loading the iSCSI initiator directly within the guest operating system and correctly configuring the target disk

The disk controller used in VMs does not have to correspond to the disk controller used in the host computer For example, you can use Serial-Attached SCSI (SAS) devices on the host server and expose them as virtual IDE devices to VMs You can also use both virtual IDE and virtual SCSI devices in a VM at the same time However, because both devices are virtual and use the same optimizations in Hyper-V, their performance is similar even though IDE and SCSI performance in the physical realm is considerably different

Keep the following rules in mind when you work with disk controllers in Hyper-V VMs:

n Use IDE only if you need four or fewer drives in the VM

n Use IDE to boot legacy VMs from VHDs or VMs that do not include Integration

More Info disk cOnnectiOns in vms

For more information on disk connections within VMs, look up Windows Server Hyper-V

Storage at

http://blogs.microsoft.co.il/blogs/dario/archive/2008/08/26/windows-server-2008-hyper-v-storage.aspx

More Info iscsi initiatOr cOnfiguratiOn

For instructions on how to perform iSCSI connections in Hyper-V, go to

http://blogs.technet.com/josebda/archive/2009/01/31/step-by-step-using-the-microsoft-iscsi-software-target-with-hyper-v-standalone-full-vhd.aspx For more information on iSCSI

and Windows Server 2008, go to http://technet.microsoft.com/en-us/library/cc771740.aspx

Working with the Virtual Hard Disk Wizard

Disk operations are performed through several different Hyper-V Manager interfaces

The first interface that gives you access to disk creation is the New Virtual Machine Wizard

Disk creation comes on the fifth page of this wizard, the Connect Virtual Hard Disk page

(see Figure 4-11) The available options are:

n create a virtual Hard disk This lets you generate a new VHD The VHD will be a

dynamically expanding VHD by default

n use an existing virtual Hard disk This lets you connect to a previously created VHD

This VHD can be any of the three VHD types

n attach a virtual Hard disk Later This lets you create the VM without a hard disk and

attach it later by editing the VM’s settings For example, you use this option when you

want to connect the VM to a pass-through disk

figure 4-11 Creating a VHD during VM creation

VHD creation is performed through the New Hard Disk Wizard This wizard gives you

several options and lets you create disks in a wide variety of styles, choosing any one of the

three VHD types (see Figure 4-12) The wizard can be accessed either through the Actions pane

in Hyper-V Manager or through the VM Settings dialog box under the controller sections

figure 4-12 Creating a new VHD

If you choose a dynamically expanding or a fixed size disk, the wizard prompts you to name the disk, choose a location for it, and then identify the size of the disk to create It also gives you the option to copy the contents of a physical hard drive into the newly created VHD (see Figure 4-13) In this case, the size of the disk will be the same size as the disk you are copying

figure 4-13 Copying a physical disk into a new VHD

If you choose to create a differencing disk in the New Virtual Disk Wizard, you will have to

specify the location of the parent disk you want to use (see Figure 4-14) Remember that as

soon as you identify a disk as a parent disk, it should be locked and used as read-only from

that point on because if the parent disk changes, the parent-child relationship will be broken

figure 4-14 Specifying the location of a parent disk for a new differencing VHD

Another interface you can use to work with VHDs and pass-through disks is the Virtual

Machine Settings dialog box (see Figure 4-15) In this case, you must begin by adding a

new hard disk You do this by selecting the controller you want to connect the disk to,

choosing Hard Drive, and then choosing Add After the hard drive has been connected to the

controller—which can be either IDE or SCSI—you can configure the type of hard drive you

want to connect In this case you are given several choices:

n You can control both the controller and the location the virtual hard disk will be

connected to

n You can select the media type:

• When you select Virtual hard disk (.vhd) file, you can either create the disk by

clicking New or connect to an existing disk by either typing the path to the VHD file

or clicking Browse to locate the existing VHD file Clicking New launches the New

Virtual Hard Disk Wizard

• When you select Physical hard disk, you must select the disk from a list of available

partitions Disks are listed as Disk 2, Disk 3, and so on Disk 1 is usually assigned to the

parent partition Remember that the disk should be offline in the parent partition to

avoid contention for disk reads and writes between the parent and the child partitions

n You can also use this interface to remove a disk from a VM’s configuration Note that this does not delete the VHD from the host’s hard drives; it only removes the VHD from the VM’s configuration.

figure 4-15 Attaching disks to a VM

You use the same interface to attach and create DVD drives to VMs (see Figure 4-16) This interface also gives you several options:

n You can control both the controller and the location the DVD will be connected to

n You can select the media type:

• New DVDs are connected to None by default

• You can also connect the media to an ISO image file ISO is a special, non- proprietary archive format used to represent the integral contents of a hard drive, CD, or DVD For example, many software vendors deliver their software products in ISO format You can use a DVD creation tool or a tool such as WinImage to convert the ISO image into another medium such as a DVD, but vendors are relying on the ISO more and more because it is one of the best mediums for populating virtual machines

• You can connect the virtual DVD to the Physical CD/DVD drive.

n You can also use this interface to remove a DVD from a VM’s configuration

figure 4-16 Attaching a DVD to a VM

More Info Winimage

Obtain WinImage from Gilles Volant Software at http://www.winimage.com

The VM Settings dialog box is also used to add or remove SCSI connectors to the VM’s

configuration In this case, you move to the Add Hardware option at the top of the left pane

in the dialog box, select SCSI Controller, and click Add As soon as you add the SCSI controller,

the new SCSI controller is highlighted and you are given the option to add a hard drive to the

VM’s configuration (see Figure 4-17)

figure 4-17 Adding a SCSI Controller to a VM

IMportant netWOrk adapters and virtuaL netWOrk adapters

Note that you also use the Add Hardware option in the VM Settings dialog box to

add either network adapters or legacy network adapters Remember that you can

add up to 8 network adapters and 4 legacy network adapters for a total of

12 adapters per VM

After the hard drive is added, you are given the same choices as when you add a hard drive to a virtual IDE controller The only difference is the amount of possible locations for the drive because Hyper-V’s virtual SCSI controllers support up to 64 locations each (see Figure 4-18)

figure 4-18 Choosing the location for a hard drive on a SCSI Controller

Editing a Virtual Hard Disk

Virtual hard disks are much more malleable than physical hard disks or even pass-through

disks because they are captured and stored within the VHD file format The best way to find

this out is to use the Edit Disk command in the Actions pane of Hyper-V Manager Edit Disk is

once again a wizard that gives you complete control over a VHD The wizard’s operation will

differ based on the type of VHD you are working with Its operation is simple:

1. Click Edit Disk in the Action pane

2. Click Next after reading the information on the Before You Begin page

3. In the Locate Virtual Hard Disk page, type the path to the disk you want to edit or

click Browse to select it Note the warning on this page concerning parent hard disks

(see Figure 4-19) As you know, parent hard disks should never be modified or the

parent-child relationship will be broken

figure 4-19 Parent hard disk modification warning

When you select the type of disk you want to modify, the wizard inspects the selected disk and provides various options based on the results of this inspection The available options (see Figures 4-20 through 4-24, see pages 252-254) are outlined in Table 4-4

tabLe 4-4 Edit VHD Options

Dynamically

Expanding

Disk

Compact Shrinks a VHD file by removing blank space that is not

removed when you delete content within the disk file VHDs are much like database files and do not remove space used by deleted data when the data is removed; therefore, you must compact the disk to recover empty space within the VHD file

Convert This converts the VHD file from dynamically expanding

to fixed disk size You must specify the location of the new fixed disk, then Hyper-V copies the contents of the dynamically expanding disk to the new fixed size disk Note that you must have enough space to store both disks during the conversion

Expand Increases the size of the VHD by a given amount You

must specify the new disk size By default, Hyper-V sets the new size at 1 GB greater than the current disk size

vHd type OptiOn descriptiOn

Fixed Size Convert This converts the VHD file from fixed size to a

dynamically expanding disk You must specify the location of the new dynamically expanding disk

Hyper-V then copies the contents of the fixed size disk

to the new dynamically expanding disk Note that you must have enough space to store both disks during the conversion

Expand Increases the size of the VHD by a given amount You

must specify the new disk size By default, Hyper-V sets the new size at 1 GB greater than the current disk size

Differencing Compact Shrinks a VHD file by removing blank space that is not

removed when you delete content within the disk file

By default, all child disks are dynamically expanding disks and therefore support the compacting action

Merge Captures the changes from the child disk and merges

them into the parent disk or another disk

Changes can be merged to the parent disk, expanding the size of the parent disk

Changes can also be merged to a new, third disk In this case, you must specify the name and the location

of the new disk as well as the type of disk: dynamically expanding or fixed size Note that you must have enough space to store all three disks during the merge operation

Reconnect (see Figure 4-24)

Appears only when a parent-child relationship is broken and lets you reconnect the child with the parent You must specify the location of the parent VHD during the reconnection

IMportant cOmpacting nOn-ntfs disks

When you compact a disk that is in NTFS format, compacting is performed without

advanced preparation But when you compact a disk that uses a format other than NTFS,

such as FAT or FAT32, you must use a non-Microsoft disk utility to replace the blank space

in the VHD with zeros The zeros are then removed during compaction Virtual Server 2005

R2 SP1 includes such a utility even though Hyper-V does not You can download Virtual

Server, uncompress the Virtual Server files, and extract the PreCompact.ISO file from the

Virtual Server installation files Then attach this file to your non-NTFS VHD and run the

pre-compaction tool on your hard drive before compacting it Obtain Virtual Server from

Microsoft at http://technet.microsoft.com/en-us/evalcenter/bb738033.aspx

figure 4-20 Available actions for dynamically expanding VHDs

figure 4-21 Available actions for fixed size VHDs

figure 4-22 Available actions for differencing VHDs

figure 4-23 Choosing merge options

figure 4-24 Reconnecting an orphan child disk

Inspecting a Virtual Hard Disk

In addition to editing VHDs, you have access to a VHD inspection tool Inspecting VHDs is relatively simple Note that inspecting can only be used to identify the status of a disk, not

to determine whether the disk is working correctly or whether it is possible to repair damage

on the disk To repair a disk, you must use the operating system’s own repair tools within the guest operating system in the VM

Inspection can be performed through the Actions pane in Hyper-V Manager or through the VM Settings dialog box when the VHD is highlighted The results of the inspection tell you what kind of disk it is and where it is located (see Figure 4-25)

figure 4-25 Inspecting a VHD

Despite the fact that inspection only gives you information about a disk, it is still quite a

useful tool because it allows you locate virtual hard disks and identify their status In resource

pools of all sizes, you will find that this tool is very useful when:

n You forget what the original size was of a dynamically expanding VHD file

n You forget where a VHD is located, especially if it wasn’t stored with the VM

configuration file

n You want to know how much space has been used in a dynamically expanding VHD file

n You want to know to which parent disk a child disk is tied

In all of these cases, Inspect Disk is often the only answer to your questions

Working with Hyper-V Snapshots

Virtual machine snapshots are a new feature of Window Server 2008 Hyper-V, as you saw

in Chapter 1 As you know, a snapshot is a point-in-time version of a VM You can take VM

snapshots when a VM is running, when it is saved, or when it is stopped Note that you

cannot generate a Hyper-V snapshot of a VM when it is in a paused state

exaM tIp creating snapsHOts

Remember that you cannot capture a snapshot when a VM is in a paused state

Each time you take a snapshot, you capture a specific point in time for a VM For example,

when a developer is working with new code and testing the operation of the code, he or she

can take snapshots of the VMs running the new application whenever a result is positive This

way, the developer can return to a stable machine state in the event that a test does not work

Another excellent example of a snapshot process is when an IT professional is performing

a complex configuration in a VM For example, when you install Windows Server 2008, Active

Directory Domain Services, Exchange Server, SQL Server, and SharePoint Server in the same

VM, you can take snapshots of the VM each time you finish installing and configuring a given

component This way, you can always go back to a given state if configuration errors occur

during the process And then, when the configuration is complete, you can merge all of the

changes into a single VHD to have an operating VHD including all of the installed components

When you revert back to a given snapshot, you revert to an exact point in time for the VM

This means that memory contents, virtual hardware, processes, machine state, and so forth

are exactly the same as when you took the snapshot When a snapshot is generated, it creates

a specific set of files, including:

n A copy of the virtual machine configuration xml file

n Any save state files (.vsv and bin)

n A differencing disk—a file with an avhd extension—which becomes a child to the

original VHD for the VM, which in turn becomes the parent for the child disk The new

AVHD file becomes the working disk for all future writes to the VM

When you create snapshots one after the other without ever applying them, you create a

snapshot hierarchy, which is a snapshot tree with a single branch When you apply a snapshot

within this hierarchy to revert to a given state in the VM and then generate new snapshots once again, you generate a new branch to the snapshot tree (see Figure 4-26)

figure 4-26 Working with a complex snapshot hierarchy

Snapshots are stored within the Snapshots folder that is created when you generate a new

VM in a specific folder Each snapshot is stored within a folder named after the GUID assigned

to the snapshot (see Figure 4-27) Remember that the original XML configuration file for the VM is stored within the Virtual Machines folder that is also created when you generate

a VM Once again, the configuration file is named with a unique GUID and saved state files are stored within a subfolder of the Virtual Machines folder that uses the same GUID as the original VM configuration filename

figure 4-27 Examining snapshot file locations

Creating VM Snapshots

You can create a snapshot in two ways: when the virtual machine is running and when the

virtual machine is turned off or in a saved state

When you create a new VM, two subfolders are created in the VM’s folder For example, if

you created a VM called VMOne on the D: drive and stored it in a folder named D:\VMOne,

the process will create two subfolders to D:\VMOne—D:\VMOne\Snapshots and D:\VMOne\

Virtual Machines D:\VMOne\Snapshots is an empty folder, but D:\VMOne\Virtual Machines

contains the original XML configuration file saved with a GUID name and a directory using

the same GUID name that will contain potential save state files (.vsv and bin), which are

in-memory files

Now if you create a snapshot when VMOne is turned off, the following process occurs:

1. Two folders are created in the D:\VMOne\Snapshots folder:

n VM GUID: a folder that will store all the avhd files for all the snapshots Note that

this folder creation only occurs for the first snapshot because all future AVHD

files will be stored here These avhd files are named with the machine name, plus

another GUID in the format of MachineName_OtherGUID.avhd

n New GUID: a folder that will store the memory save state for this snapshot In this

case, the New GUID folder will be empty since the VM is powered off and there is

no memory state

2. A copy of the VM’s xml configuration file is saved with the New GUID name

3. An avhd file is created and is stored in the D:\VMOne\Snapshots\VM GUID folder

This becomes the working avhd file This file is named with the machine name, plus

another GUID in the format of MachineName_OtherGUID.avhd

4. A pointer is added to the VM’s original xml configuration file to indentify the other

GUID avhd file as the current VHD for the VM

When you create a snapshot with the VM powered on or if the machine is in a saved

state, the exact same process occurs, except that the VM’s in-memory state is captured

to vsv and bin files These two files are stored within the folder named after the

snapshot’s GUID

If you take another snapshot of the VM, the same process occurs except that a new AVHD

file is created and this new AVHD file becomes the child to the latest running AVHD and the

latest running AVHD becomes its parent This process is repeated each time a new snapshot is

created (see Figure 4-28)

When you choose to apply a snapshot to a VM, the VM reverts to the state captured

within the snapshot and a new AVHD file is created This new AVHD file becomes the child of

the AVHD file you applied and future changes are stored within this AVHD file

Create a new virtual machine and choose Store in a different location.

Start VM and Save the state

\GUID\GUID.BIN

\GUID.VSV

Create a first snapshot while the machine is in a saved state

Create a second snapshot while the machine is in a saved state

Item in Bold/Italic are newly created or updated during the operation.

figure 4-28 The snapshot process in Hyper-V

When you revert to the original VM state through the Revert command, the current AVHD file is deleted and a new one is created to capture all changes moving forward If the snapshot was captured when the machine was running, the saved state files are applied to the

VM and the VM is restarted using these files If the VM was stopped when the snapshot was captured, the VM would remain in a turned off state

More Info Hyper-v snapsHOts

For more information on working with Hyper-V snapshots, look up the screen cast Working

with Snapshots at http://go.techtarget.com/r/5927603/30819

IMportant appLicatiOns and snapsHOts

Some applications do not support Hyper-V snapshots In addition, each time you take

a snapshot, your VHD is turned into a differencing disk and you can no longer directly

modify the parent disk

Practice Working with vm disks

In this practice you will work with virtual hard disks This practice consists of three exercises

In the first, you create a dynamically expanding disk In the second, you expand the size of

this disk to make it larger In the third, you attach a physical disk to a VM as a pass-through

disk All of the exercises are performed on ServerFull01 You log on with domain

administrator credentials to facilitate the exercise even though all you need is Hyper-V

administration rights

exercise 1 Create a Dynamically Expanding Virtual Disk

In this exercise you will create a dynamically expanding disk This exercise is performed on

ServerFull01

1. Begin by logging on to ServerFull01 Move to Server Manager and then to the Hyper-V

Manager node Select ServerFull01

2. Move to the Actions pane, select New, and then select Hard Disk Click Next

3. Choose Dynamically Expanding and click Next

4 Name the virtual hard disk dynamic.vhd and store it in a new folder in the root of

the C: drive called VHDFiles Use the Browse button to move to the C: drive, click New

Folder, type vHdfiles, and press Enter Click Select Folder and click Next.

5 Set the VHD size to 10 GB and click Finish.

Your new dynamically expanding VHD has been created Note how little time it takes

the wizard to close Open Windows Explorer (click Start and right-click Computer to select

Explore), move to the C:\VHDFiles folder, and examine the size of the new VHD It should be

approximately 82 KB in size This disk is very small because all it contains is the placeholder

for the disk and does not yet contain data

In this exercise you will choose the disk you created in Exercise 1 and expand it Once again,

you perform this exercise on ServerFull01

1. Return to Server Manager and then to the Hyper-V Manager node Select ServerFull01.

2. Move to the Actions pane and select Edit Disk Click Next

3. Click the Browse button to select the Dynamic.vhd file in C:\VHDFiles Click Open and then click Next The system inspects the disk to discover its properties

4. Click Expand and then click Next

5 Note that the wizard adds 1 GB to the disk size by default Change the value to 40 GB

and click Finish

The wizard closes very quickly once again Open Windows Explorer (click Start and right-click Computer to select Explore), move to the C:\VHDFiles folder, and examine the size

of the modified VHD It should be approximately 322 KB in size More data about the disk was added to the file, but it still does not contain any actual data, which is why it is so small

In this exercise you will connect an external hard drive to ServerFull01 and use it to create

a pass-through disk for one of your VMs Perform this exercise on ServerFull01 To perform this exercise, you need the second external USB disk as outlined in the requirements in the Introduction

1. Begin by plugging in your USB disk into a USB port on ServerFull01 Cancel the Autoplay dialog box if it opens

2. Move to Server Manager and go to the Storage, Disk Management node and click Disk Management If a dialog box appears to initialize the new volume, click OK

3. The new disk should appear as Disk 2 and should be online Right-click Disk 2, not

on its partition, and choose Offline The result should be a blank disk that is offline (see Figure 4-29) The disk is ready to be used in Hyper-V You set the disk offline to make sure the parent partition does not try to access it while a VM is using it

4. Move to the Hyper-V Manager node in Server Manager Make sure ServerFull01 is selected

5. Select WS08_Full in the Details pane and make sure it is turned off If not, click Shut Down in the VM section of the Actions pane

6. Make sure WS08_Full is selected and click Settings in the VM section of the Actions pane This opens the Settings dialog box

7. Make sure Add Hardware is selected in the left pane and SCSI Controller is selected in the right pane and click Add This adds a virtual SCSI controller and moves you to the SCSI Controller section

8. Click Add to add a new hard drive

9. Make sure SCSI Controller and 0 (In Use) are selected in the Controller and Location sections of the right pane and click Physical hard disk to select Disk 2 (see Figure 4-30) Click OK to apply your changes This adds the physical hard drive to the WS08_Full virtual machine as a physical disk connected to the virtual SCSI controller

10. The disk will appear in the VM when you launch the VM You can then use the VM’s internal tools to format and partition the disk

figure 4-29 Setting the disk as offline

figure 4-30 Attaching a physical hard disk

You have now attached a physical drive to a virtual machine.

d. The partition does not need to be formatted

2 Is it possible to store VHDs in folders that use the Encrypting File System? If not, why?

3 What are the possibilities that you can select to attach disks to VMs?

4 What are the options available when you edit a dynamically expanding virtual hard disk?

5 Which VM state does not allow you to take a snapshot of a virtual machine?Quick check answers

1 The correct answer is C The partition that stores a virtual hard disk should be formatted with NTFS.

2 You cannot store VHDs in folders that use EFS because EFS is tied to particular users and does not provide high availability because VMS stored within user profiles must run in a single user’s context.

3 Three possibilities exist when you want to attach disks to VMs: Integrated Drive Electronics (IDE), Small Computing System Interface (SCSI), and Internet SCSI (iSCSI).

4 When you edit a dynamically expanding virtual hard disk, you have three options: compact, convert, and expand

5 You cannot take a snapshot when the virtual machine is in a paused state.

case scenario: moving a virtual machine

In the following case scenarios, you will apply what you’ve learned about creating virtual

machines You can find answers to these questions in the “Answers” section on the companion

CD which accompanies this book

Contoso Ltd has been operating from several different offices around the world for several

years, but with the economic downturn, things are tight and Contoso management has had

to make some tough decisions Fortunately, they have focused on reducing expenditures

rather than reducing staff This is why they have decided to close down the London office and

relocate all personnel to New York This also means relocating the London datacenter

They have asked you, as resource pool administrator, to move your VMs from the London

datacenter to the New York datacenter Most of the virtual machines are straightforward

to move because they are nothing but a set of files in a folder All you have to do is copy

them from one location to the other Of course, it will require considerable bandwidth and

time, but it is really a simple operation However, you are concerned about the custom

banking application Contoso uses in London This VM was created using three pass-through

disks linked to a storage area network Your job is to prepare a plan to migrate this VM

from London to New York During the migration, you may need to change the nature of

the VM and management is conscious of that, but they want you to provide the utmost in

performance after the move because the VM is running a critical application Specifically,

they want you to answer the following questions:

1. How can you move the pass-through disks?

2. How will the transfer of the complete virtual machine occur?

3. How will you provide the best performance for the VM once it has been moved?

suggested practices

To help you successfully master the exam objectives presented in this chapter, complete the

following tasks

Creating and Working with VMs

n practice 1 Take the time to create basic VMs and then examine the results It is

important to understand the Hyper-V defaults and know what they are

n practice 2 Take the time to work with advanced VM settings It is important to

understand the potential settings you can assign to VMs and know what they are

n practice 3 Work with various VM states Start, stop, and reset VMs Save VM states,

pause VMs, and restart them Work to understand each state and its impact on a VM

Creating and Working with VHDs

n practice 1 Take the time to create each type of VHD Create a dynamically expanding

VHD, a fixed size VHD, and a differencing VHD Name each VHD with the disk type and then examine the results in Windows Explorer You’ll need to create a parent VHD before you create a differencing VHD Name each parent and child to understand their relationship

n practice 2 Spend considerable time with VHD snapshots The snapshot process is

a complex process and requires thorough examination in preparation for the exam Create multiple snapshots from one VM with it in all three states: started, stopped, and saved Examine the results each time in Windows Explorer Apply one of the snapshots and continue the snapshot creation process Make sure you understand this process fully before you take the exam

chapter summary

n Hyper-V can run several different operating systems including the newest versions

of Windows and special editions of Linux that have been updated to interact with

it through Hypercall Adapter In addition, Hyper-V includes Integration Services to provide additional capabilities to operating systems that are aware of the virtual environment

n Hyper-V provides Linux Integration Components to enhance Linux operating system performance when installed in Hyper-V child partitions

n Hyper-V can run legacy guests such as DOS, Windows 3.x, Windows NT, and others Legacy virtual machines are older Windows operating systems or new non-Windows non-Hyper-V-aware operating systems

n You must use the Hyper-V Input Release Key with a legacy guest operating system

to exit from a Virtual Machine Connection because these operating systems do not support Integration Services

n To create a basic virtual machine you use the New Virtual Machine Wizard The new virtual machine includes several default settings:

• 512 MB of RAM

• One processor with no reserve

• One hard drive connection and one DVD drive connection

• One virtual hard disk (.vhd) file

• Two COM ports

• One diskette drive

n Virtual machines have several advanced configuration settings that can be modified or

controlled through the VM’s settings Most of the setting changes require the machine

to be turned off

n Virtual machines can have a variety of states, and they can be controlled by selecting

the virtual machine and applying the appropriate command in Hyper-V Manager

n There are three virtual hard disk (VHD) types: dynamically expanding, fixed size,

and differencing These three types can be stored in direct-attached storage (DAS),

network-attached storage (NAS), or storage area networks (SAN)

n VHDs cannot be stored in a folder using EFS, but can be stored on partitions that use

BitLocker for added security issues

n When you create a VHD using the New Virtual Machine Wizard you have three

options: Create A Virtual Hard Disk, Use An Existing Virtual Hard Disk, or Attach A

Virtual Hard Disk Later

n A snapshot of a virtual machine creates a set of files that includes a copy of the VM

configuration xml file, any save state files (.vsv and bin), and a differencing disk with

an avhd extension You can create a snapshot when the virtual machine is running or

when the virtual machine is powered off or in a saved state

c H a p t e r 5

Automating Virtual Machine

Creation

The great advantage of working with virtual machines is that they can be deployed on

an as-needed basis almost in the blink of an eye Because most virtual machines are

nothing but a set of files in a folder—this includes any VM that uses VHDs and excludes VMs

using pass-through disks—duplicating a VM is really as easy as copying the files that make

it up and booting the new VM Of course, if you do not want an exact duplicate of a VM,

you must prepare the guest operating system through tools such as the Windows System

Preparation Tool (SysPrep.exe) to depersonalize the new copy But overall, this process can

take as little as twenty minutes Compare that to the physical machine creation process:

you must first initiate the acquisition process, configure the hardware when it comes in,

and then use a physical deployment strategy to put the server in place Physical server

deployments can easily take weeks, whereas virtual server deployment can take minutes

Week 2 Week 3 Week 4 Week 5 Week 6

Install OS Configure OSand Tools Assign IPAddress

figure 5-1 Deployment timeframes: physical machines vs virtual machine

This is why virtual machine management and operation fully support the dynamic

datacenter model If you can respond in minutes to a new business requirement, you can

dynamically provide IT services to respond to changing business conditions

In addition, virtual machines can be much more volatile than physical machines You can

spin up a virtual machine to meet a peak in business requirements and then turn it off or

simply destroy it once the need has been met For example, if your business has seasonal

fluctuations, you can create virtual machines that run desktop operating systems to support

c o n t e n t s

Before You Begin 268

Lesson 1: Exploring System Center

Virtual Machine Manager 269

Lesson 2: Automating Virtual Machine Creation 304

Manually Creating a Duplicate Virtual Machine 304

Case Scenario: Provisioning Virtual Machines 325 Suggested Practices 325

Working with the SCVMM Self-Service Portal 326 Chapter Summary 326

seasonal flux is over A good example of this is a governmental revenue agency that requires hundreds, if not thousands, of temporary employees come tax time, but that no longer needs these employees once all income tax returns have been filed

Using virtual machine management automation, you can even power up new server VMs

to support peaks in Web site access and then destroy them once the peak is over, all through automated processes that simply respond when performance measurements meet specific thresholds This is the power of virtual machine management in dynamic datacenters

But to move on to dynamic virtual machine management, you need both the proper tools and the proper processes This is the gist of this chapter

exaM tIp cOvered exams

Remember that since there are no Microsoft Press Training Kits for exams 70-693:

Windows Server Virtualization Administrator or 70-403: System Center Virtual Machine Manager 2008, Configuring, this guide attempts to perform triple duty by adding content

in support of these exams along with the content for exam number 70-652.

Exam objectives in this chapter:

n Manage templates, profile, and the image library by using SCVMM

n Create or clone a virtual machine

before you begin

To complete this chapter, you must have:

n Ideally, access to a setup as described in the Introduction In this chapter, you will begin

to work with SCVMM in earnest, and to do so you must have access to the hardware required to support host servers and VM automation

Lesson 1: exploring system center

virtual machine manager

System Center Virtual Machine Manager is a very powerful resource pool and virtual service

offering management tool It provides support for VM creation automation and host server

management

After this lesson, you will understand:

n The SCVMM user interface (UI)

n The Hyper-V through SCVMM

n The SCVMM add-ons

Estimated lesson time: 35 minutes

Working with Hyper-V Through SCVMM

You installed SCVMM in Chapter 3, “Completing Resource Pool Configurations.” This is where

you learned how powerful this tool could be to manage Hyper-V and other server virtualization

hosts The central tool for host server management with SCVMM is the SCVMM Administrator

Console This console provides several management capabilities when linked to Hyper-V:

n You can use it to deploy virtual machines regardless of the host server they will

reside on

n You can use it to convert physical machines into virtual machines (P2V)

n You can use it to convert virtual machines in a non-Hyper-V format into Hyper-V

virtual machines (V2V)

n You can use it to manage virtual machines regardless of the host the VM is located on,

as long as the host has been added to the SCVMM resource pool (see Figure 5-2)

n You can use it to view the status of virtual machines, regardless of host

n You can use it to manage template virtual machines that can be used as sources for

new VMs

n You can use it to regroup the components you need to generate new VMs and install

guest operating systems within them through the SCVMM Library

n You can use it to assign tasks to other members of your organization For example,

you can delegate SCVMM tasks to other members of the IT group through the

Administrator Console Or you can use it to delegate tasks to non-IT personnel

through the Self-Service Portal